There are two tools I have used to visualize protein-protein interactions that could be helpful to you. My favorite is Cytoscape. You can import interaction data sets and visualize them. The visualization is incredibly customizable. It also allows you to pretty easily load your data sets on top of these known interactions. And there are plugins that let you do some further analysis as well. There is a pretty steep learning curve with this one. And there are often compatibily issues with plugins that dont work with the current version. But overall, i highly recommend it.

STRING is much easier to use and allows you to perform the basic stuff that cytoscape does but without the bells and whistles. But it is user friendly and a good place to start.